1. Field of the Invention
The present invention relates in general to a weft picking device of an air jet type weaving loom, and particularly to a weft picking device of the type comprising a row of air guide members, a main nozzle, and auxiliary nozzles associated with some of the air guide members to assist the weft picking operation. More particularly, the present invention is concerned with an improvement in the auxiliary nozzle-mounted air guide member of such type weft picking device.
2. Description of the Prior Art
In air jet type weaving looms, there is known a weft picking device of the type which comprises a row of closed type air guide members by which the weft carrying air guide channel is defined, a main nozzle by which the weft thread is ejected into the air guide channel, and auxiliary nozzles which are associated with some of the air guide members to eject auxiliary air into the air guide channel to assist the weft picking operation mainly effected by the main nozzle. Each of the air guide members employed in such device has therein an air guide opening forming a part of the air guide channel, and a slit forming a part of an axially extending slot formed in the row of the air guide members. Upon beating, the picked weft thread in the air guide channel passes out of the air guide channel through the slot.
In the air jet type weaving looms, it is important but difficult to continuously carry out perfect weft picking throughout the weaving operation of the loom, in order to produce a high quality or flawless woven fabric. However, some of the conventional weft picking devices hitherto developed have sometimes suffered from a so-called weft escaping phenomenon, in that under the weft picking operation, the weft thread running in the air guide channel would pass out of the channel through the slot of the air guide members by a drawing action of the leaked air flowing through the slot. In order to solve this undesired phenomenon, various attempts have been hitherto made without satisfactory results.